1. Technical Field
Embodiments of the present disclosure are directed to a crystal display device, and, more particularly, to a liquid crystal display device providing a wide viewing angle.
2. Discussion of the Related Art
Liquid crystal displays (LCD) are widely used as a general image display device. However, despite many excellent characteristics, liquid crystal displays have a narrow viewing angle.
In the early development of liquid crystal displays, a distorted image was displayed on an inclined plane, not a front plane, but, currently, it is possible to display a reasonably high-quality image on an inclined plane due to the application of a retardation film. Moreover, with the development of a transverse electric field driving technology, there are now liquid crystal display modes that can display at a wide viewing angle even when no retardation film is used, and thus by combining a retardation film with the liquid crystal display mode, a high-quality image can been realized that is clearly superior to the early-developed liquid crystal displays.
In addition, attempts to further increase the brightness of liquid crystal display have been studied. For this purpose, a brightness enhancing film such as a reflective polarizing plate is used with liquid crystal display.
However, a conventional liquid crystal display device cannot realize a complete black state, in which no light leakage occurs, without considering wavelength dispersion because the phase differences of optical elements used in liquid crystal display change according to wavelength. Further, when a large-sized liquid crystal display device is used, image quality can deteriorate, and thus spots may appear in an image.
Moreover, when a reflective polarizing plate is used with a liquid crystal display to enhance brightness, different phase characteristics can be expressed, and thus a retardation film of a liquid crystal display should be re-designed for the liquid crystal display to have the desired phase characteristics.